Measurements of transfer process in pion capture by a series of alcohols

The transfer of negative pions captured by hydrogen to heavier atoms has been investigated in a series of alcohols by measuring both 2γ rays from π0 decay and pionic X rays. Capture rates for the pionic hydrogen of different chemical states in the molecule were determined from a comparison between the data for the ordinary compound and the deuterated one. The external transfer in the condensed phase was revealed by the dependence of the capture rate of hydrogen on the number of carbon atoms in the alkyl group. The influence of the chemical structure on the transfer process is discussed with respect to the large difference between the relative transfer rates,ΛC=1.5±0.2 andΛO = 4.5±0.4, corresponding to carbon and oxygen, respectively.